Q. My question is this: what grit is “A” grade ply sanded to from the factory? I have often wondered which grit to start with, fearing, of course, that I might inadvertently sand through the ever increasingly thin top veneer. I have asked lumber retailers that question, and no one seems to know. I hope you can shed a little light.
Rob Johnstone: Sadly, my light in this case is a bit dim. But that, of course, won’t stop me from making a recommendation. While I don’t truly know what grit the factories sand to (and I would guess it varies with the facility), I usually start with a 180-grit paper on hardwood plywood. And I usually stop at 220-grit paper. You are correct in being cautious regarding the possibility of sanding through the thin veneer. Be especially careful along edges and at corners. We often effectively end up sanding about twice as much at the end of each pass.